Rotary screw-seat



(No Model.)

L. POSTAWKA. Rotary Screw Seat.

'No. 242,474. Patented June 7,1881.

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NITED STATES PATENT ()FFICE.

LOUIS FOSTAWKA, OF OAMBRIDGEPORT, MASSACHUSETTS.

ROTARY SCREW-SEAT.

SPECIFICATION forming part of Letters Patent No. 242,474, dated June '7, 1881. Application filed January 14, 1881. (No model.)

To all whom it may concern Be it known that I, LOUIS POSTAWKA, a citizen of the United States, residing at Gambridgeport, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Rotary Screw- Seats; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanyi n g drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

This invention relates to improvements in rotary screw-seats, and it is carried out as follows, reference being had to the accompanying drawings, on which Figure 1 represents a central longitudinal section, and Fig. 2 represents a cross-section on the line A B, shown in Fig. 1.

Similar letters refer to similar parts wherever they occur on the different parts of the drawings.

a is the seat, and b b is the base or support. To the latter is secured, by means of suitable screws 0 c c, the nut d and hollow sleeve (2, as shown in Fig.1, the said nut and sleeve being for this purpose respectively provided with flanges d c, as shown.

Within the nut d is the screw f, arranged as shown, its upper end being provided with a plate, f, that is secured to the under side of the seat a, as shown. The screw fis provided with a cylindrical bore, g, into which fits the central guide-cylinder, h, the lower end of which is secured to the lower end of the sleeve 0, as shown. By this arrangement a twofold bearin g and support is given to the screw f as it is turned around its axis to raise or lower the scab-namely, one by the screw workin gwithin its nut, as usual, and the second one by the cylinder it working within the central cylindrical bore, g-as above described, by which arrangement great steadiness is obtained in the working of the screw, even if the latter should get loose by continuous wear, as it cannot rock sidewise on account of the central guide-cylinder, h, remaining within the cylindrical bore g, as set forth.

1 is a plate or washer, of wood or suitable soft or partially-yielding material, which I interpose between the flanges cl 0, so as to avoid planing or truing or finishing the lower side of flange d and upper side of flange 0; but such interposed plate is not essential in the carrying out ofm y invention, as the flange d may be made to rest directly on and be secured to the flange 6 without departing from the spirit of my invention.

What I wish to secure by Letters Patent, and claim, is

i. In a rotary screw-seat, the combination, with the seat a, of the hollow rotary screw secured to said seat, the nut d, suitably supported on the base,and the fixed rod h,rigidly connected with the base and extendinginto the bore of said screw, substantially as described, for the purpose set forth.

2. In a piano-stool, the hollow screw rigidly attached to the seat, the nut attached to the base, the sleeve 0 embracing the screw, and the rod entering the bore of the screw, said sleeve and rod being rigidly connected to the base, the'whole combined substantially as herein described.

In testimony whereof I have affixed my signature in presence of two witnesses.

LOUIS POSTAWKA.

WVitnesses:

ALBAN ANDRE'N, HENRY OHADBOURN. 

